1. Technical Field
The present invention relates to a photoelectric conversion device, an electro-optic device, and an electronic device.
2. Related Art
A photoelectric conversion device is widely being used as an image sensor in facsimiles, copying machines, video cameras, and digital still cameras. Further, an electro-optic device with a built-in photoelectric conversion element in which a photoelectric conversion element is formed integrally with a pixel portion of a display panel is also been proposed (for example, see JP-A-11-121731, JP-A-2008-85029, and JP-A-2008-122659). The photoelectric conversion device and the electro-optic device commonly have a structure in which a photoelectric conversion element including a photodiode and a thin film transistor (TFT) for amplifying and extracting a signal from the photoelectric conversion element are stacked with an insulating film interposed therebetween and connected to each other via a contact hole formed in the insulating film in order to increase the pixel density and reduce the size of an optical system.
However, in the above-described structure, since a conductive film which connects the photoelectric conversion element with the TFT becomes locally thinner due to a step difference of the contact hole portion, when a semiconductor layer (a photoelectric conversion layer) of the photoelectric conversion element is etched, the conductive film may be partially disconnected. For this reason, JP-A-11-121731 and JP-A-2008-85029 have proposed a configuration in which the photoelectric conversion element is disposed directly above the contact hole and the conductive film on the contact hole is protected by the photoelectric conversion element. However, in this configuration, since the semiconductor layer (the photoelectric conversion layer) disposed directly above the contact hole is much thinner in film thickness than other portions, there is a problem in that a leak current is generated in that portion, noise is increased, and dynamic range (sensitivity) deteriorates.